1. Field of the Invention
The present invention relates to a sustained release material which is buried at a position near to a diseased part in a living body in order to cure the diseased part inside the living body and slowly releases a liquid drug such as an antibiotics or an anticancer agent impregnated in the sustained release material beforehand, and a method of manufacturing the same.
2. Description of the Related Art
To cure osteomyelitis, tumor, cancer, or the like, an antibiotic or an anticancer agent must be administered to a diseased part present in a living body. For this purpose, a sustained release material capable of administering a suitable amount of a drug to only a diseased part in a living body has been developed.
This sustained release material can prevent problems, often observed in whole-body administration, that only a slight amount of the entire dose of a drug has an effect on a diseased part or a side effect of the administration is enhanced.
Published Unexamined Japanese Patent Application Nos. 59-101145 and 61-47401 describe techniques related to the present invention. Published Unexamined Japanese Patent Application No. 59-101145 describes a method in which a liquid drug is impregnated in a porous ceramic and the ceramic is buried in a diseased part to administer a suitable amount of the drug to the diseased part. Published Unexamined Japanese Patent Application No. 61-47401 discloses a sustained release material formed by using calcium phosphate having a large specific surface area as a base material and causing this calcium phosphate to adsorb a drug.
Since, however, the above porous ceramic or sustained release material has only a short release period for slow release of an impregnated drug, no satisfactory therapeutic effect can be obtained.
More specifically, the conventional sustained release material is obtained by causing a base material to be impregnated with or to adsorb a drug and burying it in a diseased part to release the drug, and a porous ceramic is used as the base material for obtaining this effect. However, since only few drugs can be chemically adsorbed in the base material and most drugs are only physically adsorbed therein, release of a drug cannot continue long. Therefore, it is difficult to control slow-releasing characteristics even by changing the pore size or the porosity of the porous ceramic.